The present invention relates to an electromagnetic valve comprising a solenoid portion and a valve portion, and in particular to an electromagnetic valve having constitution suitable for small-sizing.
Conventionally, as an electromagnetic valve of this kind, one disclosed in JU-A 06-071980 has been known. The electromagnetic valve is constituted by a solenoid portion provided in a cover whose one end is opened and a magnetic flame with a bobbin on which a coil has been wound, a fixed iron core mounted to a central hole of the bobbin, a magnetic plate arranged on one side of the bobbin, a movable iron core inserted slidably in the central hole of the bobbin and the central hole of the magnetic plate, and a return spring returns the movable iron core to its original position, and a valve portion provided in a valve main body with a plurality of ports, a valve seat in a passage causing these ports to communicate with one another, and valve body driven by the movable iron core to open/close the valve seat, where the solenoid portion and the valve portion are coupled relative to each other by causing a claw portion provided in a projecting manner on a side wall of the valve portion and an engagement window provided in a penetrating manner on a side of an opening of the cover to be engaged with each other and causing the resilient force due to a leaf spring provided on a bottom side of the magnetic frame to act on the engaged portion of the claw and the window.
However, since the above-described conventional electromagnetic valve requires a complicated structure where the resilient force due to the leaf spring is caused to act on the engaged portion of the claw portion and the engagement window for coupling the solenoid portion and the valve portion, it is entirely large-sized and a cost is increased. In addition, since, simultaneously with assembling of the solenoid portion, assembling to the valve portion is performed, there is a problem that consideration for performing simultaneous and accurate assembling works is required.
That is, assembling and manufacturing must be performed so as to maintain a relatively accurate positional relationship between the movable iron core in the solenoid portion and a portion to be driven in the valve portion. For this reason, it is necessary to perform assembling of the solenoid portion itself with a high accuracy and simultaneously perform positioning between the solenoid portion and the valve portion stably and accurately, and it is also necessary to obtain a sufficient coupling strength in a simple structure. However, since there are the above-described problems in the above-described conventional electromagnetic valve, it is desirable to provide means which can further simplify the structure of the solenoid and can perform assembling and coupling of the solenoid portion to the valve portion more simply and more stably.
The present invention has been made in view of the above-described problem, and an object thereof is to provide an electromagnetic valve where the structure of a solenoid portion is further simplified and assembling and coupling of the solenoid portion to a valve portion can be performed more simply and more stably.
Also, another object of the present invention is to provide an electromagnetic valve where a coupling strength of a valve portion and a solenoid portion can be secured simply at a low cost without large-sizing the solenoid portion.
In order to achieve the above-described object, an electromagnetic valve according to the present invention is an electromagnetic valve which comprises a solenoid portion where a movable iron core driven by excitation operation to a coil is provided in a magnetic case having an opening at one end and a valve portion where a valve body which is driven by the movable iron core to switch flow paths among a plurality of ports is provided in a valve body, and where the solenoid portion and the movable iron core are coupled to each other by fitting one end side of the valve body into the opening of the magnetic case, characterized in that recessed portions for engagement are provided on opposing side faces of the valve body on the side of a connection end of the valve body with the solenoid portion and inner wall faces of the recessed portions on the side of the solenoid portion are formed in an inclining face from the solenoid portion side to the other end side thereof towards a depth direction, and on the other hand, cuttings applied for forming caulking pieces are formed on a side wall of the magnetic case positioned on the side of the opening at positions corresponding to the recessed portions, and the valve portion and the solenoid portion are coupled to each other in a state that the valve portion and the solenoid portion have been biased in a direction in which they are fitted to each other by causing the caulking pieces to abut on the inclining faces of the recessed portions to caulk the caulking pieces into the recessed portions.
In the above-described electromagnetic valve, it is desirable to constitute the solenoid portion by positioning a magnetic plate to the magnetic case such that a distance between a magnetic pole face of a fixed magnetic pole member which attracts the movable iron core by a magnetic force which is formed in the magnetic case and a face of a magnetic plate which is positioned on the side of the opening of the magnetic case is fixed and fixing the magnetic plate to the side wall of the magnetic case.
In the above-described electromagnetic valve, such a constitution can be employ that the cutting provided on the side wall of the magnetic case is formed in a U-shape opened to the side of the opening end of the side wall and a region surrounded by the cutting with the U-shape is caulked into the recessed portion as the caulking piece; the cutting is formed in a straight line shape parallel with the opening end of the side wall of the magnetic case and a region positioned between the cutting with the straight line shape and the opening end of the magnetic case is caulked into the recessed portion as the caulking piece; and the cutting is formed in a thin hole bored in parallel with the opening end of the magnetic case and a region positioned between the thin hole and the opening end of the magnetic case is caulked into the recessed portion as the caulking piece.
In the electromagnetic valve having the above-described constitution, since the valve portion and the solenoid portion are coupled in a state where they have been biased in directions in which they are fitted to each other by providing a recessed portion for engagement on the opposing face of the valve body, forming an inner wall face of the recessed portion positioned on the solenoid portion side in an inclining face inclined from the solenoid portion side to the other end side towards the depth direction, while forming a caulking piece at a portion of the magnetic case corresponding to the recessed portion and causing the caulking piece to abut on the inclining face of the recessed portion to caulk it therein, the structure of the solenoid portion is further simplified as that of the conventional example, and coupling of the solenoid to the valve portion can be performed more simply and more stably. In addition, the coupling strength can be secured simply at a low cost without large-sizing the solenoid portion.
In particular, when the solenoid portion is constituted by positioning the magnetic plate to the magnetic case in the state where the fixed iron core is pressure-contacted to the inner end of the magnetic case such that the distance between the end face of the fixed iron core on the side of the movable iron core and the face of the magnetic plate positioned on the opening side of the magnetic case is fixed and fixing the magnetic plate to the side wall of the magnetic case, assembling of the solenoid portion itself can be performed with a high accuracy and simultaneously positioning between the solenoid portion and the valve portion can be performed stably and accurately.
FIGS. 1(a) to 1(c) show a first embodiment of an electromagnetic valve according to the present invention, FIG. 1(a) being a longitudinal sectional view on which a left half shows a state at a time of de-excitation to a coil and a right half shows a state at a time of excitation to the coil, FIG. 1(b) being a side view, and FIG. 1(c) being an enlarged partial sectional view of a caulking portion.
From FIGS. 2(a) to 2(c) are sectional views for explaining steps for assembling a solenoid portion in the first embodiment of the electromagnetic valve according to the present invention.
FIG. 3 is an enlarged partial sectional view for explaining a coupling method of a valve portion and a solenoid portion effected by caulking in the first embodiment of the electromagnetic valve according to the present invention.
FIG. 4 is a cross-sectional view for explaining the coupling method of the valve portion and the solenoid portion effected by caulking in the first embodiment of the electromagnetic valve according to the present invention.
FIGS. 5(a) to 5(c) show a second embodiment of an electromagnetic valve according to the present invention, FIG. 5(a) being a longitudinal sectional view on which a left half shows a state at a time of de-excitation to a coil and a right half shows a state at a time of excitation to the coil, FIG. 5(b) being a side view and FIG. 5(c) being a cross-sectional view taken along line Ixe2x80x94I.
FIGS. 6(a) to 6(c) show a third embodiment of an electromagnetic valve according to the present invention, FIG. 6(a) being a longitudinal sectional view on which a left half shows a state at a time of de-excitation to a coil and a right half shows a state at a time of excitation to the coil, FIG. 6(b) being a partial sectional side view and FIG. 6(c) being a cross-sectional view taken along line IIxe2x80x94II.